fio

Overview and history
--------------------

Fio was originally written to save me the hassle of writing special test case
programs when I wanted to test a specific workload, either for performance
reasons or to find/reproduce a bug. The process of writing such a test app can
be tiresome, especially if you have to do it often.  Hence I needed a tool that
would be able to simulate a given I/O workload without resorting to writing a
tailored test case again and again.

A test work load is difficult to define, though. There can be any number of
processes or threads involved, and they can each be using their own way of
generating I/O. You could have someone dirtying large amounts of memory in a
memory mapped file, or maybe several threads issuing reads using asynchronous
I/O. fio needed to be flexible enough to simulate both of these cases, and many
more.

Fio spawns a number of threads or processes doing a particular type of I/O
action as specified by the user. fio takes a number of global parameters, each
inherited by the thread unless otherwise parameters given to them overriding
that setting is given.  The typical use of fio is to write a job file matching
the I/O load one wants to simulate.


Source
------

Fio resides in a git repo, the canonical place is:

	https://git.kernel.org/pub/scm/linux/kernel/git/axboe/fio

Snapshots are frequently generated and :file:`fio-git-*.tar.gz` include the git
meta data as well. Other tarballs are archives of official fio releases.
Snapshots can download from:

	https://brick.kernel.dk/snaps/

There are also two official mirrors. Both of these are automatically synced with
the main repository, when changes are pushed. If the main repo is down for some
reason, either one of these is safe to use as a backup:

	https://git.kernel.org/pub/scm/linux/kernel/git/axboe/fio.git

	https://github.com/axboe/fio.git


Mailing list
------------

The fio project mailing list is meant for anything related to fio including
general discussion, bug reporting, questions, and development. For bug reporting,
see REPORTING-BUGS.

An automated mail detailing recent commits is automatically sent to the list at
most daily. The list address is fio@vger.kernel.org, subscribe by sending an
email to fio+subscribe@vger.kernel.org or visit
https://subspace.kernel.org/vger.kernel.org.html.

Archives can be found here:

	https://www.spinics.net/lists/fio/

or here:

	https://lore.kernel.org/fio/

and archives for the old list can be found here:

	http://maillist.kernel.dk/fio-devel/


Author
------

Fio was written by Jens Axboe <axboe@kernel.dk> to enable flexible testing of
the Linux I/O subsystem and schedulers. He got tired of writing specific test
applications to simulate a given workload, and found that the existing I/O
benchmark/test tools out there weren't flexible enough to do what he wanted.

Jens Axboe <axboe@kernel.dk> 20060905


Maintainers
-----------

Fio is maintained by Jens Axboe <axboe@kernel.dk> and
Vincent Fu <vincentfu@gmai